The Friedrich C-90Bis no longer manufactured.
See P600XL
for superior substitute.

Compare the Quality

The C-90B vs. HEPA filters• HEPA filters rely on the concept of
severe restriction, pushing air through tiny passages to catch particulates.
These air cleaners require considerable energy and cost to circulate enough
air to be effective.
• The C-90B uses about as much electricity as a household light bulb, as
little as 40 watts on the low fan setting.